Commercial aircraft set up for the transportation of passengers typically include rows of seats along the length of the aircraft cabin. Because the primary purpose of this type of commercial aircraft is to transport passengers, the aircraft cabin is usually set up to maximize the number of seats in the cabin. However, increasing the number of seated passengers in the aircraft cabin also increases the need for the volume of air in the aircraft to be refreshed, filtered and returned to the aircraft at a flow rate that is sufficient to keep the passengers comfortable.
Environmental control systems or air distribution systems have been developed for aircraft that continuously remove stale air from the aircraft cabin interior, pass the air through filters to sanitize the air, mix the air from the interior of the aircraft cabin with fresh air from the exterior of the aircraft and then return the refreshed air to the aircraft cabin interior. An example of such a prior art air distribution system is represented in FIG. 1. FIG. 1 is a representation of a cross-section of an aircraft with a prior art air distribution system. The aircraft 10 has an outer fuselage wall 12 that extends around the aircraft exterior and encloses the aircraft interior 14. A floor surface 16 extends across the interior 14 of the aircraft. Opposite left 18 and right 22 sidewalls extend upwardly from opposite sides of the floor surface 16 along the interior of the fuselage wall 12 and meet at the top of the aircraft interior 14. Left 24 and right 26 baggage compartments are formed in the respective left 18 and right 22 sidewalls near the top of the aircraft interior 14. Left 28 and right 32 rows of seats are positioned adjacent the respective left 18 and right 22 sidewalls and are spacially arranged along the length of the aircraft interior 14. A space is left between the rows of seats 28, 32 and forms a center aisle 34 of the aircraft.
There are cavities 36, 38 or spaces between the left 18 and right 22 sidewalls and the fuselage wall 12. The cavities 36, 38 accommodate or form portions of airflow conduits or channels that extend upwardly along the opposite sides of the aircraft interior 14. There are similar cavities 42, 44 or spaces below the opposite sides of the floor surface 16. These cavities 42, 44 also accommodate or form air flow conduits or channels extending from the respective sidewalls 18, 22 toward the center aisle 34.
The left 36 and right 38 cavities deliver a flow of air to a pair of respective left 46 and right 48 air diffusers that deliver a flow of air to an upper, center area of the cabin interior 14. These diffusers 46, 48 can be in the form of nozzles or other equivalent devices and are positioned just below the respective left 24 and right 26 baggage compartments. The cavities 36, 38 also deliver a flow of air to respective left 52 and right 54 air diffusers that deliver a flow of air to upper, outer areas of the aircraft interior 14. These diffusers can also be in the form of nozzles or other equivalent devices and are positioned at approximately head height of passengers seated in the seats 28, 32. The left 36 and right 38 cavities also deliver a flow of air to respective left 56 and right 58 air diffusers that are positioned to deliver a flow of air to lower, outer areas of the aircraft interior 14. These diffusers 56, 58 are positioned just above the floor surface 16 of the aircraft. The left 42 and right 44 cavities under the floor surface 16 deliver a flow of air to respective left 62 and right 64 diffusers that are positioned to deliver a flow of air to a lower, center area of the aircraft interior 14. These diffusers 62, 64 can also be nozzles or other equivalent devices. The diffusers 62, 64 are positioned to deliver the flow of air to an area of the aircraft interior 14 near the floor surface 16 of the aircraft and the center aisle 34.
The diffusers are each supplied with a flow of air from a pair of mixing boxes 66, 68 positioned below the floor surface 16 on the left side of the aircraft, and a pair of mixing boxes 72, 74 positioned below the floor surface 16 on a right side of the aircraft. Each of the mixing boxes 66, 68, 72, 74 receives a supply of interior air from the aircraft interior 14 that is typically drawn from the aircraft interior 14 through air returns 76 positioned at the top of the aircraft interior. The interior air is drawn through the air return 76 by fans or other equivalent devices of the aircraft air distribution system and is supplied to each of the mixing boxes 66, 68, 72, 74. The aircraft air distribution system also includes fans or other equivalent devices that draw fresh air or exterior air taken from the aircraft exterior and supply the exterior air to each of the mixing boxes 66, 68, 72, 74. In the mixing boxes 66, 68, 72, 74 the interior air and exterior air are mixed. The proportion of interior air and exterior air mixed in each of the mixing boxes 66, 68, 72, 74 is typically 50/50.
On the left side of the aircraft as shown in FIG. 1, the mixed air from one of the mixing boxes 68 is then supplied to the left air diffusers 46 positioned to the left of the upper, center area of the aircraft interior 14, and to the left air diffusers 52 positioned to the left of the upper, outer area of the aircraft interior 14. The mixed air is also supplied from the other left mixing box 66 to the left air diffusers 56 positioned to the left of the lower, outer area of the aircraft interior 14, and to the left air diffusers 62 positioned to the left of the lower, center area of the aircraft interior 14.
On the right side of the aircraft, mixed air is supplied from one of the right side mixing boxes 74 to the right air diffusers 48 positioned to the right of the upper, center area of the aircraft interior 14, and the right air diffusers 54 positioned to the right of the upper, outer area of the aircraft interior. The other of the right mixing boxes 74 delivers a supply of air to the right air diffuser 58 positioned to the right of the lower, outer area of the aircraft interior 14, and to the right diffuser 64 positioned to the right of the lower, center area of the aircraft interior.
The above described air distribution system works well, however it has a complex construction that requires a substantial amount of space in the aircraft interior. Additionally, the number of mixing boxes and the conduits communicating to and from the mixing boxes add weight to the aircraft which reduces the efficiency of the aircraft.
What is needed is a simplified air distribution system that does not have a complex construction such as that shown in FIG. 1, saves space in the aircraft interior, reduces the weight of the aircraft and handles the mixing of interior air and exterior air while also providing a drain for draining moisture condensation from the mixed air.